Steam generating attachment for electric irons



NGV. 17, 1942. M A, SQHWARTZ 2,302,264

STEAM GENERATING ATTACHMENT FOR ELECTRIC IRONS Filed April 9, 194C Patented Nov. 17, 1942 UNITED STATES PATENT OFFICE STEAM GENEBATIN G ATTACHIYIENT FOB ELECTRIC IRONS Morris A. Schwartz, Los Angeles, Calif.

Application April 9, 1940, Serial No. 328,626

Claims.

My invention relates to an attachment for an electric iron for the purpose of generating steam, the steam being discharged on the fabrics being subject to ironing. In view of the fact that the construction of steam generating electric irons are more or less complicated especially kthe type in which the generator is built into the iron and more or less directly heated by a steam heating element or by the heating unit of the iron. My invention pertains to a steam generator separate from the iron and which may be used with a conventional electric iron, the heat of the iron causing a transference to the generator and sumciently heating an ironing surface thereof. This transference of heat also generates steam from water supplied to the attachment, the steam being distributed to the fabrics being ironed through perforations in a surface of the generator. In making a steam generator of this type it must be kept comparatively light in order not to add much additional weight to that of the electric iron as well as provide a satisfactory smooth surface for ironing fabrics or the like. The materials of the generator must be of such quality and characteristics that they readily transfer the heat mainly by conduction to the ironing surface of the attachment.

Hence my invention comprehends a built up assembly of plates shaped to conform approximately to that of the bottom of a typical pressing iron and providing passages between the plates for the iiow of water, the generation of steam and the discharge 4of the steam. In order to simplify the construction and manufacture, I preferably use a lower and upper plate of the same contour both being flat and quite thin and these being separated in the assembly by a center plate which is in the form of a gasket. 'Ihis latter plate is cut prior to assembly with various slots in a more or less zig-zag manner, one of the slots connecting to the end of the center plate or gasket, therefore in the assembly there is provided by these slots a circuitous passage for the water and steam and the steam is discharged through perforations in the bottom plate adjacent the remote ends of the slots. A further detail feature of my invention is in the provision of dead ends in the zig-zag slots which form water and steam passages in which at the reverse turns of the ilow, water enters the dead ends and the steam passes in a more or less direct line of the passages. Further detail features of my invention relate to the mounting of the water reservoir, the valve control thereof and a back pressure check valve My invention is illustrated in the accompanying drawing, in which:

Fig. 1 is a side elevation taken in the direction of the arrow I of Fig. 2 showing part of the generator in vertical section as well as part of the reservoir and valve connections therefrom in vertical section, the electric iron being illustrated dotted.

Fig. 2 is a horizontal section on the line 2-2 of Fig. 1 in the direction of the arrows showing the assembly of plates with the top plate removed indicating the middle or gasket plate with the slots and passages therein.

Fig. 3 is a vertical transverse section on the line 3-3 of Fig. 2 in the direction of the arrows.

Fig. 4 is an end elevation taken in the direction of the arrow 4 of Fig. 1 illustrating the bracket support for the reservoir.

In my invention the steam generator attachment indicated by the numeral II is made up of an assembly of ilat plates having a bottom plate I2, a top plate I3 and an intermediate plate I4. These are preferably substantially the same contour except for minor changes at the rear end and approximate the outline of the bottom of a conventional electric iron. In manufacture of the plates the center plate I4 has a series of slots designated 20 formed therein of which preferably there is a central slot 2l leading from a bent-up end 22 and this end has a vertical slot 23. There are two angular branches 24 diverting rearwardly from a forwardly projecting dead end slot 25. Slots 26 parallel to 2| lead rearwardly and have a dead end 2'I adjacent which is a forwardly directed slot 28. From this there is a marginal slot 29 spaced inwardly slightly froml the edge of the plate and leading towards the front or converging points of the iron. 'I'his 'slot terminates at 30. The slots are similar and symmetrical as to the center slot 2l. This makes a balanced passage considered as to the axial center of the iron, the terminal ends 30 b eing spaced apart. These passages are thus quite evenly distributed and on account of being quite wide compared with their heighth, provide for a large heating surface for development of steam from the water and heating such steam until it is sumciently dry.

In the assembly the three plates are provided with rivet receiving holes or perforations 35 and the plates are thus assembled by a series of rivets' 36. These rivets may be countersunk as to the bottom plate if desired and are thus nished ush with both the bottom surface of the botrestricting a back flow of steam to the reservoir. tom plate and the top surface of the upper plate.

towards the rear end of the structure for satisfactory discharge of steam. 'I'he top and bottom surfaces and preferably the whole assembly of plates is plated with a suitable metal and pol- Aished thus giving a smooth surface for ironing purposes. I nnd it satisfactory to make the upper and lower plates of aluminum and the center slotted or template plate of copper. This forms a gasket and may be compressed suiilciently tight to give a leak-proof 1oint between the plates.

The water inlet passage 45 at the slot 23 is formed by an upward bend or flange 4B in the lower plate and a parallel upwardly bent flange 41 on the upper plate, this confining the upwardly bent end portion 22 of the center or gasket plate. 'Ihis produces the vertical slot 23 which has a pipe connection 4l soldered or welded to form an inlet water connection. The upper plate has a pair of iron gripping tabs or ngers 50 turned upwardly on each side of the front portion and has a pair of ears 5| bent upwardly at the rear end. These ears form a support for the reservoir bracket 52 which bracket ma.;1 be secured by screws or welding thereto. It is cbvious that this bracket could be made integral with at least the top plate I3 if desired. Through the bracket there are'threaded clamping screws 53 utilized to engage the rear end of the electric iron shown in Fig. 1 and clamp this between the tabs or gripping fingers 50, this being suiiicient to attach the equipment to the bottom of the heating iron.

The reservoir assembly 60 includes a bracket il attached to and supported at the upper portion of the reservoir bracket 52 and in this cradle there is supported a reservoir 62 illustrated as cylindrical. 'Ihis reservoir is provided with a filler opening with a conventional cap at the top. The outlet 63 at the bottom is shown as connected directly to a needle valve assembly l5. From this valve there is a union Si to which is connected a pipe coil 61 continuing and forming the pipe connection 48. This union is illustrated as having a ball check valve 6l constructed therein in that I in the needle valve construction there is a seat,y

the ball engaging therewith on the development of a back pressure of steam suilicient to force the ball against its seat. Otherwise the ball allows free passage of a slow drip of water from the reservoir.

In the manner of action and functioning of my invention as above mentioned the metal structure or plates formedthe heat transfer surface from the iron, the bottomironing surface and the intermediate channel gasket are formed of good heat conducting material as the iron relies mainly on the conduction of heat for transfer from the iron. There will also be a certain amount of convection heat due to that absorbed by the water and developed in the latent heat of steam. 'I'herefore as the water drips slowly from the reservoir into the central passage 2 I, it becomes heated and as there is a slight hydraulic head, sufficient pressure is developed to cause a flow of the water towards the front of the generator and iron. If in this passage steam is developed or water vapors, they have a tendency to drive the front portions of the water film forwardly and due to the inertia of the minute particles of water, these are carried the return directed path in the channels 24 and 28. The water in these passages becomes more highly heated developing more steam, developing a pressure drive towards the outlet and the glob- 5 ules of water are again trapped in the dead end 21. The more completely vaporized water follows the path 28 and 28 becoming quite highly heated and discharged through the perforations 40. It is obvious that the water drops trapped in the l0 dead ends 25 and 21 become heated to such an extent as to develop steam, which steam is directed from the dead end 25 along the path 24 and 26 and from the path 21 along tbe channels 28 and 28 to the outlet. It will thus be seen that the heat conducted through the attachment is suillcient not only to develop the steam but to provide suicient heat for ironing fabrics or the like and the device applying a satisfactory amount of steam for this purpose. It is manifest that if a larger amount of water is desired for the iron,

that is, the use of wet steam, the valve 65 may be so controlled and a range may be obtained figm the use of wet steam to comparatively dry s am.

An important characteristic of my invention is that the channels in the water heating and steam generating unit are of a quite small measurement considered transverse to the plates compared with the measurement in the plane of the plates, thus 30 these may be considered as very flat channels or account of steam and water being a poor conductor of heat. the thin film still allows a material proportion of the heat to pass across the channels and heat the bottom plate of the iron. therefore such bottom plate is substantially uniformly heated even although there are a number of steam and water channels. In accordance with my invention I make provision for the expansion as water generates steam since the two opposite passages 24 and 26 increase the capacity double of the channel 2i. One of the purposes of using a pipe coil 61 connecting between the reservoir and the connection 48 to the generator passage at 23 is in part to take care of expansion and contraction and also these coils form an auxiliary 50 water reservoir, hence if there is a backing up of steam the water is forced back closing the check valve 61 but as soon as the steam pressure decreases the water again immediately ows from these coils to the water and steam passages in the heating unit.

Various changes may be made in the details of the construction without departing from the spirit or scope of the invention as dened by the appended claims.

an I claim:

65 having a central slot therein extending forwardly from the back thereof, rearwardly extending branch slots extending toward the back from opposite sides of the central slot and forwardly extending side slots extending forwardly'adjacent the side margins of the middle Aplate from adjacent the rear ends of the branch slots, the bottom plate being perforated beneath the forward ends of the last-mentioned slots. and means for feeding water to the back of the central slot.

into the dead ene 2s. 'rae lighter vapors fouow "5 2. A steam generating attachment for electric irons comprising three plates attached together in superposed relationship, means for attaching the plates to an electric iron, the middle plate having a central slot therein extending forward- 1y from the back thereof. rearwardly extending branch slots extending toward the back from opposite sides of the central slot and forwardly extending side slots extending forwardly adjacent the side margins of the middle Plate from adjain superposed relationship. the central plate being slotted to provide a tortuous passageway the entrance to which is at the back oi the iron and the outlet from which is arranged in the bottom plate adjacent the iront of the iron, the three plates having extensions at their rear' ends bent upwardly, the upwardly bent extension in the middle plate having a duct communicating with cent the rear ends of the branch slots, the .bot- 10 the entrance to the passage, means for attachtom plate being perforated beneath the forward ends of the last-mentioned slots, and means for feeding water to the back of the central slot, the central plate providing wide areas between ing said plates to an iron, a bracket secured to the plates, a reservoir supported on the bracket and a conduit including a check valve leading from the reservoir to said duct in the upwardly the slots in contact with the top and bottom plates 15 bent extension in the middle plate.

for ytransmitting heat from the iron to the bottom plate by conduction.'

3. A steam generating tachment for e1ec` tric irons comprising means applicable to the 5. A steam generator for pressing irons comprising in combination an assembly of ilat plates secured together, a center plate having a series oi' connected slots completely therethrough and bottom of the iron providing a tortuous passage 20 connected together forming a circuitous water terminating in outlets adjacent the iront of the iron, means for feeding water from a main water supply to the entrance to the passage, means providing a sump for maintaining a small supand steam passage, the lowermost plate having perforations leading to the slots, said plates having an upturned anged end with a vertical slot `forming a water inlet duct, a pipe connecting ply of water adjacent the entrance to the-pas- 25 thereto, a bracket secured to the iianged end,

sage, and a check valve interposed between the sump and the main water supply for preventing reverse ow from beyond said sump to the main water supply. Y

4. A steam generating attachment for electric a reservoir supported thereby, an outlet valve from the reservoir and a check valve in the pipe connecting to the said duct.

MORRIS A.,y 

